x86/oprofile/nmi: Remove superfluous smp_function_call_single()

x86/oprofile/nmi: Remove superfluous smp_function_call_single()

Since commit 1cf4f629d9d2 ("cpu/hotplug: Move online calls to
hotplugged cpu") the CPU_ONLINE and CPU_DOWN_PREPARE notifiers are
always run on the hot plugged CPU, and as of commit 3b9d6da67e11
("cpu/hotplug: Fix rollback during error-out in __cpu_disable()")
the CPU_DOWN_FAILED notifier also runs on the hot plugged CPU.
This patch converts the SMP functional calls into direct calls.

smp_call_function_single() executes the function with interrupts
disabled. This calling convention is preserved.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Robert Richter <rric@kernel.org>
Cc: rt@linuxtronix.de
Cc: oprofile-list@lists.sf.net
Link: http://lkml.kernel.org/r/20161117183541.8588-19-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>